1. Field of the Invention
This invention is related to an image scanner. More specifically, this invention relates to a cordless image scanner used for reading handwritten pictures or drawings.
2. Related Art
FIGS. 5-7 illustrate a conventional image scanner 50. An image sensor 51 can read handwritten pictures or drawings. A binary means, which may be a half tone processor circuit 56, converts the analog data accumulated by the image sensor 51 and transmits the converted data to a CPU 52. The CPU 52 processes the data read by the image sensor 51 and then sends such data to a personal computer or a word processor, either of which constitutes a host computer 60. The transmitted data is stored in the memory of the host 60 and displayed on its display screen 60a.
A LED array 53 is used as a light source and emits light onto the surface of a script to illuminate an image. A rotary encoder 54 defines the scope of image inputting by regulating the scope of the imaged picture. Controller or PIA (peripheral interface adapter) circuit 55 controls the LED 53 and the rotary encoder 54 and monitors the ratio of distance covered with respect to the light flashes emitted by the LED 53. A start switch 57 is turned on when it is desired to image data. A zoom switch 58 allows the image scanner 50. Finally, a programmed ROM 63 is used for compressing system data.
In FIG. 6, the image scanner 50 is linked to interface B by cable 61 and is detachably connected to the host computer 60 via the interface B. On the other hand, in FIG. 7, information is supplied through a cable 61 and a standard interface RS232C. In the conventional image scanner 50, not only the display of stored image data but also the power supply are dependent upon host computer 60. It is impossible to use the image scanner 50 by itself; the use of the image scanner 50 is limited to places providing a host computer 60. Subsequently, handwritten drawings or pictures cannot be freely input everywhere.
Another drawback with the conventional image scanner 50 stems from the cable 61 which connects the host 60 to the image scanner 50. When an operator inputs images from a script, for example, 100 images, the operator must grasp the image scanner 50 in his hand and slidably move the image scanner 50 across the script for each image. This movement is not only hindered by the tension in the cable 61 but also such hindrance may induce distortion in the images produced.